Self-locking duplex box



May 25 1926. 1,585,783

S. W. MASON SELF LOCKING DUITLEX BOX Filed July 13, i925 g m en/m; w I(v MM Patented May 25, 1926.

will" STT SINGLETON W. MASON, OF KANSAS CITY, MISSOURI, ASSIGNOR OFTWO-THIRDS TO THOMAS L. COCKRELL, OF KANSAS CITY, MISSOURI.

SELF-LOCKING DUPLEX BOX.

Application filed July 13, 1925 Serial No. 43,162. i

This invention relates to cardboard boxes or cartons for candy and thelike, and more especiallyto boxes or cartons which may be utilized fordisplaying their contents and also used as shipping boxes. One of theobjects of the invention is to produce a box or carton of this characterfrom a blank by the folding thereof-and in which means is provided forautomatically locking thebody of the box in completed form by securingthe ends of the-box against accidental opening movement.

Another object s to provide an improved type of folding cover, which canbe slid back to vertical open position, and will automatically lockitself for the display of the contents of the box and of advertising orother matter on the cover.

A further object is to produce a carton of the character described whichis of simple, strong, durable and inexpensive construction; and in orderthat it may be fully understood, reference is to be had to theaccompanymg drawing, in which Figure 1 is a perspective view of a boxconstructed in accordance with the invention as it will appear when inopen or display position.

Figure 2 is a section on the line II--II of Figure 1.

Figure 3 is a central vertical transverse section through the box inclosed position.

Figure 4 is a section on the line IV-IV of Figure 1.

Figure 5 is a view of one end of the box in unfolded position.

Figure 6 is a section on the line VIVI of Figure 4.

. Figure 7 is a plan View of the blank from which the box is formed.

In the said drawing, where like reference characters identifycorresponding parts in all of the figures, the carton is shown as madeup of a generally rectangular strip of 5 cardboard or other suitablematerial, there being a flap portion 1, a top portion 2, cutout toprovide a display opening 3, a front side 4, a bottom 5, a rear side 6,and a cover portion scored longitudinally to provide two half portions 7and 8, and a tab, 9.

The parts are folded in the order mentioned and the flap 1 is glued orotherwise secured to the inside face of the back or side 6. A The cover7-8 overlies thetop 2 and "closes the opening 3, and has lts integraltab 9 bent and engaged with a slot 10 along the meeting lines of theside 4 and the top 2. The tab 9 is formed with a semi-circular tongue 11which engages with a slot 12 formed in the rear side of the top 2, whenthe cover is in open position as shown clearly in Figure 1, it beingapparent that the two halves of the cover 78 are folded as illustrated,and that the exposed or vertically standing portion of the'part 7provides a convenient surface for carrying an advertisement or name ofthe manufacturer or other matter.

The opposite ends of the sides 4 and 6 are respectively provided withend flaps 13 and 14 which are longer than half the in terior width ofthe box, the flaps 13 and 14' of the opposite ends of the boxoverlapping each other as illustrated, the flaps 13 having their uppercorners cut away as-at 15 for a purpose which will hereinafter appear.The top 2 is formed along its opposite end edges with end portions 16,said end portions each having flaps17 rounded at their ends' At the endsof the junction or fold lines between the end portions 16 and the flaps17 are notches 18, which leave the rounded extremities of the flaps 17,constituting locking lugs 19. r

When the parts have been folded as 'described and the members 13 and 14are closing the ends of the box and are overlapping each other, the endportions 16 are folded, down outside of said members 13 and 14, and theflaps 17 being ,equal 'in width to the width of the bottom 5 before thebox is folded, are now slightly greater in width than the insidedimensions of the box. It, therefore, follows that the lugs 19 slightlybow upward in the process of forcing the flaps 17 between the bottom 5and ting the lugs 19 to lock themselves in position by engagement withthe'inner faces of the parts 13 and 14. It will now be apparent that theupper corners of the parts- 13 are preferably cut away in order to allowthe ends 16 to be bent downwardly without producing an unsightly bowingor protuberance along its upper portion, as would b p and bottom membersand front and rear sides, each side having end portions p rojectingtoward the other side and forming inside end walls of the box, and oneof the said members having ends fitting against the outer sides of therespective end portions and flaps extending into the box between thesaid end portions and the inner face of the other member; the ends ofsaid. flaps having lugs extending augularly and bearing against theinner faces of the said end portions to lock the said ends of the topflatly against the said end portions of the sides.

2. A box of flexible material having top and bottom members and frontand rear sides, each side having end portions overlapping at their freeends and forming inside end walls of the box, and the said top memberhaving depending ends fitting against the outer sides of the respectiveend portions, and flaps extending into the box below the said endportions and bearing against the inner face of the said bottom member;the ends of the said flaps having lugs extending angularly and bearingagainst the inner faces of thesaid end-portions to lock the said ends ofthe top flatly against the said end portions of the sides.

3. A box of flexible material having top and bottom members and frontandrear sides, each side having end portions projecting toward the otherside and forming inside end walls of the box, and one of the saidmembers having ends fitting against the outer sides of the respectiveend portions, and flaps extending into the box beflaps having notchesforming end lugs bearing against the inner faces of the sides of the boxand extending angular-1y and bearing against the inner faces of the saidend portions of the sides to lock the said ends of the top flatlyagainst the said end portions of the sides.

4. In a box of flexible material, top and bottom members, and sides,each side having end portions extending respectively toward the otherside, one of said members having ends fitting against the outer sides ofthe said end portions, and flaps interposed between the other member andthe adjacent edges of the end portions, said flaps having at theiropposite free extremities, lugs extending angularly and engaging theinner faces of the said end portions to secure the said ends of the saidmember flatly against the adjacent end portions.

5. In a box of flexible material, top and bottom members, and sides,each side having end portions extending respectively toward the otherside, one of said members having ends fitting against the outer sides ofthe said end portions, and flaps interposed between the other member andthe adjacent edges of the end portions, said flaps having taperedextremities and notches, forming end lugs of such extremities extendingangularly and engaging the inner faces of the sides and the said endportions to secure the said ends of the said member flatly against thesaid end portions.

6. A flexible blank for producing a box, comprising a rectangularportion to form a cover, a rear side, a bottom, a front side having anopening and a flap for fastening to the upper part of the rear sidebelow the cover; the cover having a tab and the latter a tongue, and thetop a front slot for the receptionv of such tab; and a rear slot for thereception of said tongue; each side having oppositely projecting endportions, and the top having ends terminating in tapered flaps andnotched at the ends of its junction line with such flaps to providebendable tapered lugs. p

In witness whereof I hereunto affix my signature.

SINGLETON w. MASON.

